Apparatus to dispose of gaseous monomer

ABSTRACT

Apparatus for removing gaseous monomer emitted during the manufacture of polymer fibers collects the gaseous monomer in a suction nozzle constructed of smooth polymeric material having low heat conductivity to avoid monomer buildup therein and delivers same upwardly through a water trap to a transport duct which is kept sufficiently wet to receive and remove monomer solids carried in the water which flows by gravity in the duct.

BACKGROUND OF THE INVENTION

This invention relates to monomer exhaust systems for use in syntheticfiber manufacture.

During the extrusion of synthetic polymers to make fibers such as nylon,that monomer portion which does not polymerize must be disposed of. Ithas been the practice in disposing of monomer gas to connect an upperpart of the quench cabinets, wherein the monomer gas is formed adjacentthe spinnerets, to an exhaust duct thereabove by means of round flexiblepipes. A fan in the exhaust duct pulls a vacuum in the pipes. Themonomer gas, as it cools, sublimates or collects as a solid andaccumulates inside the walls of the pipes and duct and eventually causesclogging problems, which cause production shut down and the necessaryclean up in order to get the exhaust system working properly. It isoften necessary to melt out the monomer accumulations in the pipes andduct.

Accordingly, it is an important object of this invention to provide animproved apparatus for disposing of gaseous monomer developed during theprocess of quenching fibers extruded in the spinnerets.

Another important object of the invention is to avoid monomer build upin the ducts and pipes utilized to dispose of quench cabinet monomergas.

Still another important object of this invention is to provide animproved system for disposing of gaseous monomer in a form adaptable tosatisfy environmental concerns.

SUMMARY OF THE INVENTION

The invention contemplates disposing of gaseous monomer developed in theextrusion of plastic fibers wherein air flow is utilized of quenchingthe extruded fibers prior to winding by providing a plurality oflaterally spaced nozzles constructed of a polymer having low heatconductivity each receiving air flow containing gaseous monomer on oneend and delivering same in an upwardly directed stream on the other end.A water tight duct receives the upwardly directed air flow streams atlongitudinally spaced locations therealong. Spray nozzles are spacedalong the duct delivering water for containing the monomer solids formovement responsive to air flow along the duct for removal. An uprightconnector joins each of the nozzles and the water tight duct fordirecting the air flow stream into the duct.

BRIEF DESCRIPTION OF THE DRAWINGS

The construction designed to carry out the invention will be hereinafterdescribed, together with other features thereof.

The invention will be more readily understood from a reading of thefollowing specification and by reference to the accompanying drawingsforming a part thereof, wherein an example of the invention is shown andwherein:

FIG. 1 is a perspective view schematically illustrating a monomerexhaust system, constructed in accordance with the invention, installedupon quench cabinets; and

FIG. 2 is an enlarged perspective view illustrating a nozzle connectedto an exhaust duct in accordance with the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT

The drawings illustrate apparatus for disposing of gaseous monomercontained in the fumes emitted in the area adjacent the spinneretsduring the manufacture of synthetic fibers. Spaced suction nozzles A fordrawing in fumes containing gaseous monomer are constructed of a smoothpolymer having sufficiently low heat conductivity to maintain the fumesin the nozzle at a elevated temperature to avoid excessive monomersublimation and accumulation therein. A transport duct B has sufficientair flow to remove fumes by suction through the nozzles and into theduct. Apparatus C is provided for injecting water into the fumes in thetransport duct in sufficient quantity to carry off the solidifiedmonomer therein. Junctions are provided with water traps D between thenozzles and the transport duct delivering the fumes to the transportduct avoiding the back flow of water containing monomer from thetransport duct into the nozzles. A mounting provides for the transportduct to be suitably positioned to carry off the water containing monomerby the force of air flowing along the duct. Monomer buildup is avoidedthrough the construction of the nozzles and the wetting of the duct tocarry off the collected monomer by gravity.

A series of quench cabinets are schematically illustrated at 10, eachhaving a number of strands of extruded fiber 11 proceeding from thebottom thereof. Adjacent the tops 12 of the cabinets, the nozzles A areillustrated as being in a position to draw off monomer exhaust fromwithin the cabinets above a front cabinet wall 13.

The nozzles A are best illustrated in FIG. 2 and include an enlargedopen end 14 formed by an expanded section 15 which converges toward aconnector 16 illustrated as being of uniform cross section. A seal isformed by a plate 18 having a slot 19 cut therein opening toward theexpanded or flared end of the nozzles and which accommodates an opening20 in the upper surface 17 through which monomer gas is passed upwardlyinto the exhaust duct B. Spacer blocks 21 are provided for positioningthe plate 18 above the upper surface 17 of the nozzles in order toaccommodate a base of a stand pipe which forms a part of the water trapD.

The transport duct B is open on one end as at 22 and is connectedthrough a curved duct 23 and a square to round 24 and through a circularpipe 25 to an exhaust fan 26. It will be noted that a number of spacedservice access doors 27 having handles 28 are provided along the ductfor servicing the junctures between the nozzles and the duct for readilyremovably receiving the nozzles and for cleaning the duct and forgeneral service work.

The apparatus C for injecting water into the transport duct includes alongitudinal pipe 29 having a number of nozzles 30 for providing a sprayof water across the interior of the duct and, in particular, across themonomer gas laden air. It will be noted that the exhaust duct B issupported by the duct work and any other suitable support structure inorder to be positioned substantially horizontally as shown so that airflow will induce flow of the water into which the monomer has sublimatedtoward the exhaust duct work for removal by gravity. The water trap Dincludes threaded stand pipe 31 which has an upper surface 32 extendingabove the surface of any liquid accumulations adjacent the bottom 33 ofthe transport or exhaust duct B. A seal is provided by a lower gasket 34which is tightened against the bottom 33 as by a spud nut 35. A similarnut 35 may be utilized to tighten the gasket 36 against the uppersurface of the bottom 33.

OPERATION

It is thus seen that gravity causes the flow of water containing themonomer to flow downwardly and through the exhaust duct work. Themonomer solids are kept in the spray water collected in the transportduct.

It is important to note that the nozzles are constructed of a materialhaving a low thermal conductivity such as suitable polymer, for example,Lexan plastic or Lucite plastic, so as to be smooth and non-corrosive.It is important that the surface be smooth so as to be resistant toseeding of the monomer gas as may cause excessive monomer collections tobuild up within the nozzles. Since the material is of low thermalconductivity, little heat transfer is permitted by the nozzles inrespect to flow of monomer gas passing therethrough to the transportduct reducing any tendency toward monomer buildup.

It is thus seen that a system of disposing of gaseous monomer collectedadjacent the spinnerets of a fiber extrusion process has been providedso as to avoid monomer build up in the duct work. The expensivemaintenance work normally associated with cleaning the duct work anddisposing of the monomer collected in the duct work has been avoided.Another important advantage is achieved because the water carrying themonomer solids may be more easily disposed of.

As illustrated the air and fumes enter a suction nozzle and travelthrough the suction nozzles to an exhaust duct. The exhaust duct inletextends into the duct to prevent water leakage even when the nozzle isremoved. A water spray scrubs monomer fumes from the air stream, and thewater/monomer solution drains to an effluent handling system.

While a preferred embodiment of the invention has been described usingspecific terms, such description is for illustrative purposes only, andit is to be understood that changes and variations may be made withoutdeparting from the spirit or scope of the following claims.

What is claimed is:
 1. Apparatus for disposing of gaseous monomercontained in the fumes emitted in the area adjacent the spinnerets inthe manufacture of synthetic fibers comprising:a plurality of laterallyspaced suction nozzles, each of said nozzles drawing in fumes containinggaseous monomer from the area adjacent the spinnerets at an enlargedopen end; a transport duct having sufficient air flow to remove fumesfrom said nozzles and into the transport duct; a portion of said nozzlesopposite said enlarged open end extending across said transport duct;apparatus for injecting water into said fumes in said transport duct insufficient quantity to carry off said monomer therein; a plurality ofjunctions carried by a bottom portion of said transport duct anddisposed between said portions of corresponding nozzles and said bottomportion delivering said fumes to the transport duct avoiding the backflow of water containing monomer from the transport duct into thenozzles; and said suction nozzles being insertably received for drawingin said fumes at said enlarged open end and by said duct for readyremoval for cleaning.
 2. The structure set forth in claim 1 wherein saidjunctions each include a water trap having an upright connector with anupper surface extending above said bottom portion of said transport ductsufficiently to avoid overflow of water containing monomer therein. 3.The structure set forth in claim 2 including an opening in an uppersurface of said nozzle remote from said spinnerets beneath saidtransport duct and a seal slidably receiving said upright connector.